Senator Kirk’s central claim is that the world has reverted to 1938 and that the regime in Tehran should be compared to Nazi Germany on the eve of World War Two.

"David Cameron must choose between two Conservative legacies," thunders Senator Kirk, "that of Winston Churchill or that of Neville Chamberlain."

Really? At Munich 1938 Hitler was already embarked on his wars of conquest. He’d left the League of Nations, had occupied the Rhineland, annexed Austria, and was poised to invade Czechoslovakia.

Iran has not invaded another country in the last 170 years and is not threatening to do so now. It as one of the original signatories of the Nuclear Non-Proliferation Treaty in 1968 and submits its nuclear facilities to international inspection.

The analogy with Hitler and appeasement (which was also used by neo-Conservatives ahead of the Iraq War) is tired and feeble.

As for his remark about Iran's facilitation of al Qaeda, this shows that Senator Kirk deserves to be dismissed as an ignoramus whose advice on tying one's shoes should be treated with the utmost caution.